Centering block for positioning reinforcement iron pieces

ABSTRACT

A centering block for positioning reinforcement iron pieces, in a mould adapted for manufacturing concrete building elements, the said block comprising a circular plastic member provided with a central channel and with peripheral radially arranged branches, the said channel forming a plurality of recesses of decreasing sizes adapted for lodging iron pieces of different sizes.

United States Patent [1 1 Cennerelli CENTERING BLOCK FOR POSITIONING REINFORCEMENT IRON PIECES [76] Inventor: Giuseppe Cennerelli, 8, Cite Jean Grenmillon, Bobigny, France I [22] Filed: Jan. 6, 1972 [21] Appl. No.: 215,800

[30] Foreign Application Priority Data Jan. 6, 1971 France 7100230 [52] U.S. CI. 52/687 [51] Int. Cl. E04c 5/16 [58] Field of Search 52/687, 688, 689, 52/684, 677

[S6] References Cited I UNITED STATES PATENTS 3,360,898 1/1968 Beckman 52/689 X FOREIGN PATENTS OR APPLICATIONS 1,375,489 /1964 France 52/677 [111. 3,783,574 [451 Jan. 8, 1974 1,573,010 /1969 France 52/684 1,484,976 /1969 Germany 52/684 1,178,193 /1964 Germany 52/687 432,788 /1967 Switzerland 52/684 Primary Examiner-Frank L. Abbott Assistant Examiner-Carl D. Friedman AttorneyWilliam A. Drucker [57] ABSTRACT A centering block for positioning reinforcement iron pieces, in a mould adapted for manufacturing concrete building elements, the said block comprising a circular plastic member provided with a, central chanhe] and with peripheral radially arranged branches, the said channel forming a plurality of recesses of decreasing sizes adapted for lodging iron pieces of different sizes.

3 Claims, 3 Drawing Figures CENTERING BLOCK FOR POSITIONING REINFORCEMENT IRON PIECES This invention relates to a wedge designed to be positioned at substantially regular intervals over a mesh of reinforcing rods and to enable the latter to be put in position at the bottom of a mould suitable to take a concrete mix for the manufacture of a reinforced precast unit, e.g., for the manufacture of a building unit such as a concrete panel.

When manufacturing building units of this kind, the reinforcement, made up of round rods assembled to form a mesh or grid, is placed at the bottom of the mould. These reinforcing units have to be kept at a certain distance from the bottom of the mould so that, as the concrete sets, they are inserted inside the building unit at the required distance from each of the two edges and, preferably, substantially in the middle of the thickness of the panel so that the latters internal strength is balanced.

Wedges designed to enable reinforcing rods to be positioned at a suitable distance and kept evenly spaced from the bottom of the mould are already known. These wedges usually comprise a hollowed-out centre designed to take the reinforcing rod and a peripheral part designed to rest on the bottom of the mould.

These wedges are advantageously made of moulded plastic, which allows a certain amount of flexible deformation and holds the reinforcing rod better, this being kept in its socket and prevented from moving under the thrust of the concrete mix when the latter is put in.

Known wedges usually have the disadvantage that they comprise an inside socket the gauge of which corresponds to a specific reinforcing rod diameter, so that each size or each profile of reinforcing rod calls for a type and size of wedge corresponding exactly to the reinforcing rod in question; the result is that manufacturing and positioning costs are excessive and the storing of the various types of wedges gives rise to problems.

US. Pat. No. 3,449,882 (W. OTT) suggested the inclusion in the wedge of a'V-shaped inside groove, divided by lugs into two sockets-suitable to take two reinforcing rods with different diameters, inserted by spreading the stays of the groove apart. Various other kinds of sockets have been suggested to take two or three reinforcing rods with slightly different diameters,

but none of these devices makes it possible to take, and hold firmly enough, the whole range of reinforcing rods in current use, whose diameters may, e.g., vary from several millimetres to several centimetres.

Moreover, the shapes of known wedges are not usually satisfactory: they are too bulky, they resist the passage of the concrete and create a weak area in the latter; moreover, more often than not they comprise projections which are visible on the surface of the panel after casting, giving rise to the risk of cracking and of moisture penetrating to the reinforcing rods.

French Pat. No. 1,375,489 (DOWTY) suggested making the wedge in the general shape of a circular crown from which points radiate in a star-shape, providing a purchase on the bottom of the mould without any visible projections. However, as the profile of these points is symmetrical in relation to the median plane of the crown, the purchase on the mould is unstable. In addition, the reinforcing rod is merely held inside the crown by flexible lugs, which only enables a very small range of diameters to be used.

Finally, in all known devices, the distance between the reinforcing rod and the purchase on the mould cannot be adjusted, which means that several types of wedges have to be provided for each reinforcing rod diameter to take into account the fact that the reinforcing rod must be embedded in a greater or lesser thickness of concrete according to the building requirements.

This invention overcomes these various disadvantages and covers the manufacture of a wedge for the positioning of reinforcing units in a mould of the type which comprises a circular grooved part to enable the reinforcing rods to be inserted between two flexible lips and form sockets suitable to take the said reinforcing rods, and a plurality of points radiating in a star-shape around the said part, the said wedge being chiefly characterised by an elongated groove which winds in a loop so as to go round a substantial part of the circumference of the said part and whose edges narrow-progressively from an opening giving on to the outside to the end of the said loop, the said groove comprising,

opposite one another on its edges, projections delimiting a plurality of sockets with decreasing gauges.

A wedge of this kind can be positioned on reinforcing rods with varying sections, the user merely having to use that one of the sockets which corresponds to the section of the reinforcing rod to be held, and place the wedge so as to obtain the required spacing between the reinforcing rod and the bottom of the mould.

Other characteristics and advantages of the invention will clearly emerge from the following specification.

In the attached drawing:

FIG. 1 is a plane view of a wedge in accordance with one embodiment of the invention, wherein several reinforcing rodshave been inserted.

FIG. 2 is a plane view of the same wedge, with the reinforcing rods removed.

FIG. 3 is a sectional view along the line III+III in FIG. 2.

The wedge in accordance with the example shown is made of moulded plastic and is in the general shape of a star, consisting of a central core 1 from which branches 2a, 2b, 2a, 2b radiate and whose points rest on the bottom of the mould and constitute the wedges purchase. This purchase, limited to the points of two neighbouring stars, is practically invisible on the surface of the panel after casting. There is therefore no risk of cracking or of moisture penetrating to the reinforcing rods. The branches are pyramidal in shape with a triangular base, hollowed out as shown e.g., at 2b, which improves their anchorage in the concrete.

It can be seen that branches 2a 2""a have their hollowed-out sides facing towards theunderside of the part, while branches 2b 2"b have their hollowedout sides facing towards the surface shown in the draw- FIG. 3 shows that the open bases of the branches 2a, 2a are in the plane of one of the surfaces of the part, while the open bases of branches 2b, 2b are in the plane of the other surface. The result of this staggering is that the points of two neighbouring branches such as 2a, 2b provide a comparatively stable purchase on the bottom of the mould.

In the core 1 there is a groove 3 giving on to the outside at 4 and enabling reinforcing rods to be inserted into it. The groove follows a generally curved line which goes round the circumference of the core 1. The

edges of the groove 3 comprise facing projections 5 and 5, 6 and 6', 7 and 7', delimiting internal sockets with decreasing gauges 8, 9, etc. These sockets can take reinforcing rods 8', 9', 10' etc. (FIG. 1) whose diameter may e.g., vary from 2 to 24 mm.

The reinforcing rod is inserted into the wedge via the opening 4 until it reaches the socket corresponding to its size, in which it is then completely locked.

By positioning the wedge suitably in relation to the mould, the distance between the centre of the reinforcing rod and the wall of the mould can be varied. For example, taking reinforcing rod 10, it is obvious that there will be a minimum distance (e.g., 2 cm) between it and the wall of the mould if the wedge rests on points 2'a, 2b, while there will be a maximum distance (e.g., 4 cm) between it and the wall of the mould if the wedge rests on points 2b 2""a. The distance can be varied gradually between these two limits.

It goes without saying that the dimensions indicated are not limitative, and that details may be modified without thereby departing from the scope of the invention.

I claim:

1. In a device for positioning reinforcing units in a mould, comprising a disc having an eccentric C shape slot therein of tapering width and opening out between two flexible lips and forming sockets for the said reinforcing units, and a plurality of peripheral anchoring branches radiating in a star-shape around the disc, the improvement in which the slot follows a curved line going round a substantial portion of the circumference of the said part and the edges of which narrow from the said lips to the far end of the said curved line, said slot including a plurality of sockets with decreasing gauges.

2. In a device in accordance with claim 1, the improvement in which each of said branches is in the shape of a hollowed-out pyramid.

3. In a device in accordance with claim 2 the improvement including two sets of hollowed-out pyramidal branches, the hollowed-out surfaces of the branches of the two respective sets being positioned respectively in two planes symmetrically arranged in relation to the median plane of said circular disc part, the branches of one of the sets alternating with the branches of the other. 

1. In a device for positioning reinforcing units in a mould, comprising a disc having an eccentric C shape slot therein of tapering width and opening out between two flexible lips and forming sockets for the said reinforcing units, and a plurality of peripheral anchoring branches radiating in a star-shape around the disc, the improvement in which the slot follows a curved line going round a substantial portion of the circumference of the said part and the edges of which narrow from the said lips to the far end of the said curved line, said slot including a plurality of sockets with decreasing gauges.
 2. In a device in accordance with claim 1, the improvement in which each of said branches is in the shape of a hollowed-out pyramid.
 3. In a device in accordance with claim 2 the improvement including two sets of hollowed-out pyramidal branches, the hollowed-out surfaces of the branches of the two respective sets being positioned respectively in two planes symmetrically arranged in relation to the median plane of said circular disc part, the branches of one of the sets alternating with the branches of the other. 